Issue 22, 2017, Issue in Progress

Wetting mechanism of a PVDF hollow fiber membrane in immersed membrane contactors for CO2 capture in the presence of monoethanolamine

Abstract

As an emerging technology, membrane gas absorption (MGA) contactors for carbon dioxide (CO2) capture exhibit great advantages compared to conventional chemical CO2 absorption processes. However, the decline in membrane flux, caused by the membrane's wetting, is a serious technical problem. In this study, to better understand the wetting mechanism of a polyvinylidene fluoride (PVDF) hollow fiber membrane in an immersed membrane contactor for CO2 capture, a 30 day operation of CO2 absorption was conducted, in which, 2 M monoethanolamine (MEA) solution and deionized water were used as the absorbents. The results showed that the presence of MEA in the absorbent solution aggravated the wetting phenomenon, thus significantly decreasing the membrane flux and membrane hydrophobicity. X-ray photoelectron spectroscopy (XPS) and attenuated total reflection-infrared spectroscopy (ATR-IR) analyses for the wetted membranes proved that no chemical reactions occurred between the MEA and the membrane. Furthermore, no hydrophobic components of the wetted membrane dissolved in the MEA solution. Instead, the presence of MEA was observed in the cross-linked network of the membrane wetted by the MEA absorbent. Field emission scanning electron microscope (FE-SEM) images of the outer surfaces of the wetted membranes suggested that the membrane morphologies changed and the membrane walls thickened, especially for the membrane wetted by the MEA absorbent. Both the presence of MEA molecules in the cross-linked network of the wetted membrane and the thickening of the membrane wall were important characteristics of membrane swelling. The changes in mechanical strengths of the wetted membranes also testified that membrane swelling occurred. Based on the above results, it was concluded that the membrane swelling caused the membrane wetting in the immersed PVDF membrane contactor for CO2 capture, and the presence of MEA in the absorbent further aggravated the process of membrane swelling.

Graphical abstract: Wetting mechanism of a PVDF hollow fiber membrane in immersed membrane contactors for CO2 capture in the presence of monoethanolamine

Article information

Article type
Paper
Submitted
22 Dec 2016
Accepted
16 Feb 2017
First published
28 Feb 2017
This article is Open Access
Creative Commons BY-NC license

RSC Adv., 2017,7, 13451-13457

Wetting mechanism of a PVDF hollow fiber membrane in immersed membrane contactors for CO2 capture in the presence of monoethanolamine

Z. Zhang, X. Wu, L. Wang, B. Zhao, J. Li and H. Zhang, RSC Adv., 2017, 7, 13451 DOI: 10.1039/C6RA28563E

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements